1. Field of the Invention
This invention relates to vibratory structure for dislodging and separating sand and scale from castings.
2. Background Art
In many foundry operations, separation of sand and scale from castings is required. Typically, the castings are initially tumbled to dislodge foreign matter adhering to the castings. To assist this dislodging, shot may be caused to impinge upon the castings as they are tumbled. An exemplary structure through which dislodging of foreign matter according to the above can be accomplished is shown in U.S. Pat. No. 3,793,780 to Musschoot.
In the Musschoot U.S. Pat. No. 3,793,780 a tipped, U-shaped hopper is provided and has independently operable, vibratory imparting mechanisms associated with each leg of the hopper. Operation of the vibratory imparting mechanism is coordinated to move the casting towards a dead zone for tumbling and shot treating and away from the dead zone upon completion of the tumbling and treating operations to discharge the castings.
The principal difficulty with this type of equipment is that the vibration is not imparted continuously during the separating operation. Rather, the vibration imparting mechanisms are stopped and started, requiring monitoring and coordination. Aside from the above, the intermittent operation of the vibration imparting mechanisms results in possible excessive wear thereon.
Another drawback with the equipment in the prior art is that intermixing of the castings with the shot, the separated sand and the scale occurs. In some prior art, it is intended that sand and shot remain in the hopper with the castings as the castings are agitated and transported for discharge. The discharging castings therefore can retain some of the shot, sand and scale. In the event that engine blocks or the like are cast, complete removal of sand, scale, shot and other foreign matter is absolutely essential. Thus, with the prior art structures, a subsequent cleaning operation would have to be performed on the cast parts.